Sure, everyone may have own trading strategy because everyone has a different style and goal in trading. Some people trade daily, they want faster profits. While others may not trade daily and don't hurry to take profits. So, their goals and style are not the same, they need a different strategy.

By the way, it is true that a certain strategy may work effectively with us. But it may not work effectively to other people. However, I don't think there is a strategy that can harm people as long as the people know well their goal.